Gravely 522 ? Rebuild

[Mattc8832]

I finally got the Kohler 8hp rebuilt. It now has over 100 LBS of compression. I still have a bit of a knock or ticking sound to the engine. Is this just the nature of this old engines. The more throttle I give the engine the louder the knock or ticking sound. Any ideas.

 

[js5020]

Did you bore the cylinder or just put a new set of rings in it? Check the point timing also.

 

[Mattc8832]

Just put new piston and rings in.

 

[js5020]

I have a 12hp walk behind and knowingly put a new piston and rings into an engine that tossed a rod and that should have been bored as it had/has a tick/knock that gets louder as rpms are increased, I attribute the noise to excess clearance around the piston allowing it to "slap" the cylinder wall and upon careful inspection the rod makes slight contact with the cylinder wall at a point in the stroke. I have 2 of these K series engines a 12 and a 16 and both show/have shown the tendency to egg the bores and taper them without leaving much visual evidence but bore gauges tell the real story. These are 40yr old engines and darn good ones(both of mine are still STD) but at 40yrs old most need bored as the bores are no longer on the tight side of the spec. The 12 has been running for 3yrs with its tick/knock, I just don't wind it all the way up or blow snow with the unit,, maybe Ill get the time to do a proper rebuild with a cyl bore this year? and if not Im sure it will keep on keeping on.